Effects of antegrade cardioplegic infusion with simultaneously controlled coronary sinus occlusion on preservation of regionally ischemic myocardium after acute coronary artery occlusion and reperfusion

This study was conducted to assess the protective effects of antegrade infusion of cardioplegic solution with simultaneously controlled coronary sinus occlusion on regionally ischemic myocardium after acute coronary occlusion and reperfusion. Twelve sheep were subjected to 1 hour of occlusion of the distal left anterior descending coronary artery. Sheep in group I (n = 6) were subjected only to infusion of potassium crystalloid cardioplegic solution into the aortic root, whereas in group II (n = 6) a stitch was snared around the proximal coronary sinus for its subsequent occlusion during antegrade infusions of cardioplegic solution. All animals were placed on cardiopulmonary bypass. Five hundred milliliters of cardioplegic solution at 4 degrees to 8 degrees C was administered in three divided doses during the total cross-clamp period of 30 minutes. The occlusion of the left anterior descending artery was then released, and the animals were weaned from bypass and studied for an additional 4 hours. Coronary sinus pressure, myocardial temperature, regional function assessed by pairs of ultrasonic crystals, global function assessed by rate of rise of left ventricular pressure and cardiac output, and the area at risk and area of necrosis were determined. The heart was excised at the end of the experiment and stained. Animals treated by the technique of antegrade infusion combined with coronary sinus occlusion had more homogeneous myocardial cooling during cardioplegic infusions and better recovery of the first derivative of left ventricular pressure and regional segment shortening at 90 and 270 minutes of reperfusion than those treated with antegrade infusion alone (p less than 0.01 and p less than 0.05, respectively). The group treated by antegrade infusion of cardioplegic solution combined with coronary sinus occlusion had an area of necrosis/area at risk ratio of 40.5% +/- 1.2%; the antegrade infusion group, 58.3% +/- 4.1% (p less than 0.01). These data suggest that antegrade infusion combined with coronary sinus occlusion may be an improved method of global and regional myocardial protection in the presence of an occluded coronary artery.     

Does the angiotensin receptor blocker telmisartan prevent morbid atherosclerotic events?

ONTARGET has established the efficacy of the angiotensin receptor blocker (ARB) telmisartan to slow disease progression and delay or prevent morbid events in patients with atherosclerosis. Although the study failed to confirm additive efficacy of telmisartan and the angiotensin-converting-enzyme (ACE) inhibitor ramipril, caution should be exercised in assuming that the mean response in a clinical trial applies to individual patients who might benefit from combination therapy. Physicians should also recognize that the design of the study, in which full doses of the ACE inhibitor and the ARB were administered, might not replicate clinical practice, where one drug is usually added to the other.     

CentriMag left ventricular assist system: cannulation through a right minithoracotomy

The CentriMag left ventricular assist system can be used for perioperative or postcardiotomy circulatory support of the failing heart. The device resides at the patient's bedside, and the cannulae are usually inserted through a midline sternotomy, with the inflow cannula in the left ventricle or right superior pulmonary vein and the outflow cannula in the aorta. In a patient whose chest has been closed and who has a delayed need for temporary mechanical support, a less invasive method of left ventricular assist device cannula insertion is preferred. In these cases, the CentriMag cannulae can be inserted through a right minithoracotomy with the inflow cannula in the right superior pulmonary vein and the outflow cannula in the aorta, with no heparinization. Herein, we describe this approach in a patient who experienced postcardiotomy cardiogenic shock after aortocoronary bypass surgery. This technique may facilitate ambulation and recovery in selected patients.     

Pericardial Access Through the Right Atrium in a Porcine Model

As procedures such as epicardial ventricular ablation and left atrial appendage occlusion become more commonplace, the need grows for safer techniques to access the physiologic pericardial space. Because this space contains minimal fluid for lubrication, prevailing methods of pericardial access pose considerable periprocedural risk to cardiac structures. Therefore, we devised a novel method of pericardial access in which carbon dioxide (CO₂) is insufflated through a right atrial puncture under fluoroscopic guidance, enabling clear visualization of the cardiac silhouette separating from the chest wall. We performed the procedure in 8 Landrace pigs, after which transthoracic percutaneous pericardial access was obtained by conventional means. All of the animals remained hemodynamically stable during the procedure, and none showed evidence of epicardial or coronary injury. The protective layer of CO₂ in the pericardial space anterior to the heart facilitated percutaneous access in our porcine model, and the absence of complications supports the potential safety of this method.     

Serum lipid levels in angiographically defined coronary artery disease.

To evaluate the association between serum cholesterol and triglyceride levels and angiographically determined coronary artery disease, two selected groups of 100 patients each were compared. The coronary artery disease group had significantly higher serum levels of both cholesterol and triglyceride. However, several types of analyses based on the quartile distribution of serum levels of cholesterol and triglyceride showed that the serum cholesterol level was more significantly associated with coronary artery disease than was the triglyceride level. This was especially true in relation to multivessel disease, the most severe form of coronary artery disease, and most marked in men. Association with coronary artery disease appeared to be continuous, rather than being related to any critical serum level, thus re-emphasizing the need to distinguish between desirable and average levels of serum cholesterol in countries with a high dietary intake of saturated fat.     

A-HeFT: old dog, new endothelial tricks

In conclusion, reduced nitric oxide bioactivity contributes to cardiac and vascular remodeling. Nitricoxide-enhancing therapy can slow cardiac andvascular remodeling. African-Americans with heart failure exhibit nitric oxide deficiency and a dramatic benefit from nitric-oxide-enhancing therapy. The potential benefit of this therapy in other groups with heart failure and in other vascular remodeling disease processes requires further study.